Elastomeric surgeon's gloves have very demanding requirements. They should have film strength to resist tearing, low thickness to allow touch sensitivity, and enough flexibility to handle a medical tool. Furthermore, they should be easy to don with both wet and dry hands, but not be slippery when handling instruments. Traditionally, surgeon's gloves have been manufactured by dipping hand-shaped molds into baths containing natural rubber latex, polyisoprene latex, nitrile latex, polychloroprene latex, and polystyrene butadiene latex to form a film of the desired thickness. The film is then cured and removed from the mold as a glove. Numerous problems are associated with the manufacturing of such elastomeric gloves. Removal of the gloves from the mold can be difficult because the gloves tend to be tacky and may adhere to the mold. In addition, the gloves adhere to themselves and prove difficult for a surgeon to don. Techniques for addressing these problems have been developed over the years. Initially, in order to strip a glove off a mold, powders were dusted onto the surface of the mold and the outer surface of the glove. Since the gloves are generally turned inside out as they are stripped from the molds, these powders then aid the subsequent donning of the glove by a surgeon. A wide variety of powders have been used including talc, lycopodium, calcium carbonate, starch and modified starch. Granuloma formation in patients was identified and attributed to powders, particularly when using talc and its use has long since been abandoned. As an alternate to powder, there are many disclosures of coating or treatments of gloves to modify their surface properties. These surface modifications have enjoyed some degrees of success. There are two general ways to accomplish the surface modifications: chemical treatment and coating materials onto a glove surface. Chlorination is representative of the chemical treatment. Chlorination renders a rubber surface slippery, but it is most effective in dry hand donning and additionally, the treatment may weaken and em brittle the overall film. It may also adversely affect the shelf life of a sterile glove. There are many disclosures relating to coating materials onto a rubber surface to improve its slip characteristics with both wet and dry skin. Representatives of the disclosures are as follows:
U.S. Pat. No. 4,575,476 to Podell, et al. describes a dipped rubber article having a skin contacting surface layer formed of a hydrogel polymer. Gloves prepared according to the teaching of Podell, et al. partially delaminate and release particles from the hydrogel coating. Furthermore, they tend to be somewhat thicker than many commercial gloves, thereby adversely affecting tactile sensitivity.
U.S. Pat. No. 5,612,083 to Haung, et al. demonstrates that a multi-layer flexible article includes a first layer of natural rubber; a second layer of natural rubber, polyurethane, poly(acrylamide-acrylic acid, sodium salt) and polyethylene oxide; and a third layer of acrylic copolymer and fluorocarbon telomer resin. These polymers as demonstrated by Haung, et al. do not have crosslinking characteristics to hydrate and hold at least 200% of water. The patient contacting surface of this technology is also very tacky when compared to the glove produced from the present invention.
U.S. Pat. No. 6,706,313 to Goldstein, et al. describes a water soluble hydrophilic resin and a method of application to natural rubber and synthetic latex products. Gloves prepared according to the teaching of Goldstein, et al. have low mechanical strength and loose particles from the coating. Furthermore, they tend to be somewhat thicker than many commercial gloves, thereby adversely affecting tactile sensitivity. U.S. Pat. No. 8,110,266 to Chen, et al. demonstrates that the internal surface of an elastomeric article is coated with a polyisoprene coating. This patent does not mention a third layer of hydrophilic polymer as the present invention to crosslink and form an uneven surface, thereby rendering the article substantially less textured and less comfortable in wear compared to articles as prepared and treated in the present invention.
U.S. Pat. No. 9,579,426 to Chen, et al. describes that the internal surface of the elastomeric article is coated with a polyisoprene coating. This patent does not mention a third layer of hydrophilic polymer as the present invention to effectively swell into enlarged water gel during washing, leach out allergenic impurities and shrink back to form an uneven surface after drying, thereby rendering the article substantially more toxic and less comfortable in wear compared to articles as prepared and treated by the present invention.
U.S. Patent Application No. 20170107403 to Woo, et al. shows a water-based hydrogel polymer coating and a method of application to natural rubber or other elastomeric latex products. This application does not mention hydrophilic polymers in the second and the third layers as the present invention which allow the glove to effectively swell into enlarged water gel during washing, leach out allergenic impurities, and shrink back to form an uneven surface after drying, thereby rendering the article substantially more toxic and less comfortable in wear compared to articles as prepared and treated in the present invention.
None of the foregoing examples disclose a multilayered process to make an elastomeric article with hydrophobic polymers as a patient contacting layer, hydrophilic polymers as a wearer contacting layer, and the polymers blended from both layers of polymers as an intermediate layer between two contacting layers. The hydrophilic polymers are crosslinked. Consequently, they texturize a wearer contacting surface, increase water absorption capability, and boost leaching effectiveness. The textured surface reduces contact points for the hand to slide in and out. Therefore, the friction force between hand and glove surface is significantly reduced. High water absorption minimizes the uncomfortable feeling from excessive sweating. The effectiveness in leaching makes the article less cytotoxic and more suitable for wearing.